摘要
为比较四川牦牛常规粗饲料的营养价值,试验选用燕麦干草、青贮燕麦、天然牧草,对其进行营养成分和体外产气分析。体内消化试验于四川省红原县进行,选取9头初始体重为(150±10)kg的麦洼公牦牛,随机分为3组,每组3头牛。试验结果如下:1)天然牧草粗蛋白(crude protein,CP)含量显著高于青贮燕麦和燕麦干草(P<0.05);天然牧草的中性洗涤纤维(neutral detergent fiber,NDF)和酸性洗涤纤维(acid detergent fiber,ADF)含量显著低于青贮燕麦(P<0.05);2)康奈尔净碳水化合物蛋白质动态评价体系(cornell net carbohydrate and protein system,CNCPS)中,青贮燕麦的非蛋白氮(non-protein nitrogen,PA)部分显著高于燕麦干草和天然牧草(P<0.05);天然牧草的快速降解蛋白(rapidly degraded protein,PB1)、慢速降解蛋白(slowly degraded protein,PB3)含量最高,且不可降解蛋白(undegraded protein,PC)含量最低;青贮燕麦的不可利用纤维(undegraded fiber,CC)含量显著高于天然牧草和燕麦干草(P<0.05);可利用纤维(available fiber,CB2)、非结构性碳水化合物(non-structural carbohydrates,NSC)含量显著低于天然牧草和燕麦干草(P<0.05);3)天然牧草的NDF、CP消化率均显著高于燕麦干草和青贮燕麦(P<0.05);天然牧草ADF消化率显著高于青贮燕麦(P<0.05),与燕麦干草差异不显著(P>0.05);4)天然牧草牦牛瘤胃液的NH3-N浓度显著高于青贮燕麦和燕麦干草组(P<0.05),而其微生物蛋白质(microbial crude protein,MCP)产量显著高于燕麦干草组,与青贮燕麦组差异不显著;燕麦干草总挥发性脂肪酸(total volatile fatty acid,TVFA)产量最高;5)天然牧草组的产气量显著高于青贮燕麦组(P<0.05),与燕麦干草组差异不显著(P>0.05);体外降解方面,燕麦干草的体外干物质降解率(in vitro dry matter digestibility,IVDMD)、体外中性洗涤纤维降解率(in vitro neutral detergent fiber digestibility,IVNDFD)、体外酸性洗涤纤维降解率(in vitro acid detergent fiber digestibility,IVADFD)最高,其中,IVDMD显著高于青贮燕麦(P<0.05),与天然牧草差异不显著(P>0.05);IVNDFD、IVADFD与其他两种饲草相比差异均不显著(P>0.05)。综上,CNCPS分析的各组分含量所反映的瘤胃发酵状况、体外产气法所测定的结果与牦牛体内消化试验测定的各养分消化率和瘤胃代谢产物结果基本吻合,3种饲草的营养价值由高到低依次为天然牧草>燕麦干草>青贮燕麦。
This experiment compared the nutritional value of forages conventionally fed to yaks in Sichuan.Oat(Avena sativa) hay,oat silage and Sichuan pasture were analyzed for their nutritional value and in vitro gas production.An in vivo digestion experiment was conducted in Hongyuan,Sichuan Province.Maiwa male yaks(n=9)with an initial body weight of 150±10 kg were randomly divided into 3 treatment groups with 3 yaks in each group.It was found that:1)The crude protein(CP)content of pasture was significantly higher than that in oat silage and oat hay(P<0.05).The neutral detergent fiber(NDF)and acid detergent fiber(ADF)content of pasture was significantly lower than that in oat silage(P<0.05).2)The non-protein nitrogen content in oat silage was significantly higher than that in oat hay and pasture(P<0.05).The rapidly degraded protein,moderately degraded protein and slowly degraded protein contents in pasture were the highest and the unavailable protein content was the lowest.The unavailable fiber content in oat silage was significantly higher than that in pasture and oat hay(P<0.05),while the slowly degraded fiber and non-structural carbohydrate contents were significantly lower than those in pasture and oat hay(P<0.05).3)The NDF and CP digestibility of pasture were significantly higher than those of oat hay and oat silage(P<0.05).The ADF digestibility of pasture was significantly higher than that of oat silage(P<0.05),but did not differ significantly from that of oat hay(P>0.05).4)The NH-N concentration in the rumen fluid of yaks in the pasture treatment group was significantly higher than in animals fed oat silage and oat hay(P<0.05),and the micro crude protein yield was significantly higher in the pasture diet than that in the oat hay diet but did not differ significantly from that in the oat silage diet.Oat hay had the highest total volatile fatty acid yield.5)The gas production of animals fed pasture was significantly higher than that of animals fed oat silage(P<0.05).Overall,rumen fermentation results reflected the predictions from diet component analysis using the cornell net carbohydrate and protein system(CNCPS)and in vitro gas production results were basically consistent with the results of nutrient digestibility and rumen metabolites determined by the yak in vivo digestion test.These results indicate that it is feasible to evaluate the nutritional value of yak roughage using the CNCPS and in vitro gas production methods.The nutritional values of the three forages were:pasture>oat hay>oat silage.
作者
游茵洁
周浩珍
刘垚
王晨曦
彭忠利
YOU Yin-jie;ZHOU Hao-zhen;LIU Yao;WANG Chen-xi;PENG Zhong-li(College of Animal Husbandry&Veterinary Science,Southwest Minzu University,Chengdu 610041,China)
出处
《草业学报》
CSCD
北大核心
2022年第8期99-110,共12页
Acta Prataculturae Sinica
基金
牦牛短期育肥关键技术集成示范与研究(280330013501)
国家现代农业技术体系四川肉牛创新团队建设项目(sxcxtd-2020-13)资助。
关键词
CNCPS
体外产气法
牦牛
cornell net carbohydrate and protein system
in vitro gas production
yak nutrition
